Question about Prolog/XPCE

General
1

Hi,
after a long break, I’ve restarted playing with SWI-prolog and its graphical object-oriented extension XPCE lately and I would like to know: is there a way of adding information to the general clause

send(Obj, open)

in such a way that the Obj window doesn’t open randomly (or following the default values), but rather in a precise part of the screen? Because if I don’t set specific parameters I always get the window opened in the wrong place (overlapping other windows for example).
Thanks for your answer and thank you all for the development of SWI-Prolog during all these years.
Marco

2

Sorry about the late answer, XPCE is old and it has a small number of users, it is mainly used in the GUI of Swi-Prolog.development tools

This example should work from the command line

new(Frame,frame),new(P,point(400,300)), send(Frame, open(position := P)).
3

Thank you PasiK! So the trick is to create two objects (a frame/window and a point) and then add that the window should open at that point with the specification (position := ObjRef) to the send(Obj, open) clause. Apropos XPCE: I also had the impression that it is no longer developed/maintained, but I don’t know why I was interested in it. Thanks a lot!

4

XPCE looks visually like from 1990’s, but I have began to really appreciate it. Eric Zinda in his blog wrote about it as fast prototyping tool.

Yes a professional tool and in the old days professional tools didn’t care much about visual bling bling :slight_smile:

5

Ok. Thanks a lot for the reference to Eric Zinda’s blog. Excuse me…but I’m learning to do stuff :sweat_smile:

6

Actually the idea that I’d like to work on is to use xpce and its drawing capabilities to build a little system that draws syntactic labelled parse trees out of prolog compound terms/lists representing parsed sentences with their syntactic structure (S, NP, VP, Det… and so on…) and then with the lexical items. But I don’t know: a) is it possible (in principle it doesn’t seem impossible at least), b) will I be patient enough to carry out the task? I’ll let you know if I make any progress :wave:

7

A common way of doing this is to use GraphViz by generating a description of the graph in DOT. And there are other tools such as https://www.tomsawyer.com/ .

8

Thank you. I imagined that someone might have already developed something similar. I’ll give a look at those things.

9

Jan actually have provided some of the basic tools in SWISH. But there is still value in XPCE, I hope you will succeed with your task.

10

At the moment I’m trying with the dot language which peter ludemann suggested because the syntax is very simple and it doesn’t seem impossible to build a pipeline in three steps: prolog file > .gv file > .svg file. At least that’s what I have in mind. I’ll let you know. Swish is really a great thing. I agree

11

Well, I’m quite happy to say that it worked! I’m a happy man :sweat_smile:
The grammar is really primitive: it only tackles simple sentences with a subject, a verb and an optional adverbial modifier like [a, boy, eats, slowly] or [the, cat, silently, sleeps] and so on. The basic ideas are contained in Bramer’s Logic programming with Prolog and Learn Prolog Now! by Blackburn, Bos and Striegnitz.

A predicate takes as input a sentence (represented as a list of words) and outputs a parsed structure like

Parse = s(np(det(the), n(cat)), vp(adv(silently), v(sleeps)))

then this thing is processed and output to a .gv file which has the following look:

strict graph  {
    node [shape=plaintext]
    s -- {np vp}
    np -- {det n}
    det -- the
    n -- cat
    vp -- {adv v}
    adv -- silently
    v -- sleeps
}

This in turn is translated into a graph by writing at the terminal window
“dot -Tsvg file.gv > file.svg”

Thanx for the suggestions :+1:

12

Not sure if you tried to upload the *.gv and *.svg files here to show others but you should be able. :slightly_smiling_face:
If not let me know, I have admin rights on this site.

For an example of such uploaded files see this reply.

I am curious see them.

13

No, I didn’t. But I will upload the two *.svg files here

first
second

14

the two *.gv files:

first.gv (129 Byte)
second.gv (105 Byte)